Watchdog Finds Evidence That Iran Worked on Nuclear Triggers

The world’s global nuclear inspection agency, frustrated by Iran’s refusal to answer questions, revealed for the first time on Tuesday that it possesses evidence that Tehran has conducted work on a highly sophisticated nuclear triggering technology that experts said could be used for only one purpose: setting off a nuclear weapon.

Statistics in the report also indicated that Iran has begun to recover from the effects of the Stuxnet computer worm, which first struck the country nearly two years ago in an apparent effort to cripple its production of nuclear fuel. Based on recent visits by inspectors, the agency concluded that Iran’s main production site at Natanz is now producing low-enriched uranium at rates slightly exceeding what it produced before being hit by the Stuxnet. The computer worm appears to have been designed in a secret project in which the United States, Israel and some European allies all played a role, The New York Times reported in January.

In a separate report on Syria, the agency also laid out a detailed case, for the first time, that the country was “very likely” building a secret nuclear reactor that should have been reported to the agency. The facility was bombed by Israel in September 2007, and Syria quickly bulldozed the site, eliminating most of the evidence.

Although the C.I.A. released photographs in 2008 of the reactor building, taken before the bombing raid, the agency’s inspectors in Vienna had at first been quite skeptical of any evidence provided by the Bush administration, with which they had clashed over the status of Iraq’s nuclear program. But they have now come to the same conclusion that Washington came to nearly four years ago, and American officials said they plan to use the report to press the agency’s board of governors at its meeting next month to refer the issue to the United Nations Security Council for possible sanctions.

“We fully expect the board of governors to address these issues with the seriousness they deserve,” Glyn T. Davies, the American ambassador to the I.A.E.A., said in a telephone interview from Vienna.

But at a moment when the Syrian government is struggling to stay in power amid uprisings, the shooting of protesters in Syrian towns will almost certainly seem like a more urgent matter for the United Nations to address. The apparent effort by the Assad government to build a nuclear capacity, with help from North Korea, is likely to be viewed as what one American official called “a historical event, not an ongoing threat.” Even if the reactor was solely for energy production, the country would be required to tell the agency and place the facility under its safeguards.

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A satellite image from Aug. 5, 2007, showed a Syrian facility that the International Atomic Energy Agency now says was “very likely” a secret nuclear reactor.Credit
DigitalGlobe, via Associated Press

On Tuesday, Israel’s prime minister, Benjamin Netanyahu, at a joint session of Congress, urged the United States not to take the threat of military action against Iran’s nuclear facilities off the table.

“The ayatollah regime briefly suspended its nuclear program only once, in 2003, when it feared the possibility of military action” after the invasion of Iraq, Mr. Netanyahu said. “That same year, Muammar Qaddafi gave up his nuclear weapons program, and for the same reason. The more Iran believes that all options are on the table, the less the chance of confrontation.”

Mr. Netanyahu has been far more assertive than his American counterparts in making public threats about potential military action; the Stuxnet operation, which American and Israeli officials refuse to discuss, appears to have been part of an effort to come up with a covert, nonmilitary solution.

The Stuxnet may have now run its course. David Albright, president of the Institute for Science and International Security, a private group in Washington that tracks nuclear proliferation, analyzed the I.A.E.A. report and concluded that the jump in monthly production of enriched uranium was “the highest level that Iran has ever achieved.”

The official American and Israeli estimates suggest Iran is still at least a year, and most likely several years, from being able to produce a bomb. Iran says its nuclear program is meant only to produce energy, but many Western countries believe the country is hiding a weapons program.

“The agency has not described these experiments to this detail before,” said Olli Heinonen, the agency’s former chief inspector.

Starting in early 2008, the agency has repeatedly accused Iran of dragging its feet in addressing “possible military dimensions” of its nuclear program. Tehran has declared that all of the evidence gathered by the agency — mostly from the intelligence agencies of member countries, and some from its own inspectors — are fabrications.

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The site was bombed by Israel and cleared by Oct. 24, 2007.Credit
DigitalGlobe, via Associated Press

The I.A.E.A.’s last report, issued in February, listed seven outstanding questions about work Iran apparently conducted on warhead design. The documents in the hands of the agency raise questions about work on how to turn uranium into bomb fuel, how to cast conventional explosives in a shape that can trigger a nuclear blast, how to make detonators, generate neutrons to spur a chain reaction, measure detonation waves and make nose-cones for missiles.

Tuesday’s report gave new details for all seven of the categories of allegations. The disclosure about the atomic trigger centered on a rare material — uranium deuteride, a form of the element made with deuterium, or heavy hydrogen. Nuclear experts say China and Pakistan appear to have used the material as a kind of atomic sparkplug.

The report said it had asked Iran about evidence of “experiments involving the explosive compression of uranium deuteride to produce a short burst of neutrons” — the speeding particles that split atoms in two in a surge of nuclear energy. In a bomb, an initial burst of neutrons is needed to help initiate a rapid chain reaction.

Harold M. Agnew, a former director of the Los Alamos weapons laboratory, said the compression of uranium deuteride suggested work on an atomic trigger.

“I don’t know of any peaceful uses,” he said in an interview.

The agency’s disclosure about Iran’s alleged use of uranium deuteride also suggests another possible connection between Tehran’s program and Abdul Qadeer Khan, the rogue Pakistani engineer who sold nuclear information.

A famous photograph of Dr. Khan, whom Pakistan has released from house arrest in Islamabad, shows him in front of the schematic diagram of an atom bomb on a blackboard. A pointer to the bomb’s center is labeled uranium deuteride.

Tuesday’s report also gave fresh charges on the design of missile warheads. Documentary evidence, it said, suggested that Iran had conducted “studies involving the removal of the conventional high explosive payload from the warhead of the Shahab-3 missile and replace it with a spherical nuclear payload.”

The Shahab-3 is one of Iran’s deadliest weapons, standing 56 feet tall. In parades, Iran has draped them with banners reading, “Wipe Israel off the map.”

A version of this article appears in print on May 25, 2011, on Page A4 of the New York edition with the headline: Watchdog Finds Evidence That Iran Worked on Nuclear Triggers. Order Reprints|Today's Paper|Subscribe